The proposed research is designed to psychophysically investigate retinal regional differences in visual function. Specifically, perimetric measures of various aspects of color vision and temporal resolution will be studied. It is hypothesized that retinal regional differences in these measures can be attributed to differences in the spatial spread over which lateral interactions take place. Consequently, it is predicted that the same visual performance will be measured throughout the retina, given appropriate compensations in stimulus size. Thus, the proposed experiments will be performed as a function of stimulus area. Because of the lack of perimetric data on color vision and temporal resolution, the proposed experiments will be repeated on a sufficient number of observers to establish norms. Thus, many of the measures may later be adapted for application to clinical research.